As French President Francois Hollande embarks on a state visit to the US, the BBC uses pictures to look back at the highs and lows of the two countries' relations.

US President Barack Obama (left) and his French counterpart Francois Hollande reflect on their countries' historic friendship at the start of Mr Hollande's state visit to the US with a tour of the residence of the third US President Thomas Jefferson, one of the earliest American envoys to France

After Washington, Mr Hollande will go to Silicon Valley in California, to meet tech leaders - and hopefully bring some start-up spirit back to the stagnant French economy

He is not the only French president to hope some Silicon Valley sparkle rubs off on him, but he will be the first since Francois Mitterrand (centre left) met a 29-year-old Steve Jobs there in 1985, two years after this US summit

The Iraq war, which French Foreign Minister Dominique de Villepin (bottom left) tried to block from his seat in the UN Security Council, was a low point in bilateral relations

Angry at French obstructionism at the UN, restaurants in Congress renamed French fries "freedom fries"

And it was not just the politicians - several private restaurants also protested against French tactics with their menus

Trying to patch things up, Nicolas Sarkozy - dubbed "l'Americain" (The American) in France, for his Anglicised, pro-business stance - paid a working visit to the US after his election in 2007

But the last formal, state visit to the US, was by President Jacques Chirac, here flanked by President Clinton in 1996

President Valery Giscard d'Estaing (left) redefined the concept of the flying visit in 1976, arriving by supersonic jet Concorde for a six-day official trip to see Gerald Ford

The two countries fought together in World War Two - here US President Roosevelt, (centre left) and British Prime Minister Churchill, (right) helped plan the Normandy landings with French Generals Henri Giraud (left) and Charles de Gaulle

Thousands of Americans died during the D-Day attacks on the French coast

But the French-US alliance goes much further back - to the US war of independence from the UK in the 18th Century, while the Statue of Liberty was a gift from France in 1886